Acoustic guide for noise-transmission testing of aircraft
First Claim
1. A method for acoustic testing of interior cabin noise levels in assembled, full-scale vehicles which allows selective testing of installed components and subassemblies comprising the following steps:
- sealing an acoustic guide to a noise source and to a test component such that noise impingement is restricted to the test component only;
transmitting noise into the acoustic guide;
directing said noise from the acoustic guide on to a component or subassembly of a test object;
measuring noise energy delivered to the exterior of the test component;
measuring noise energy transmitted through the test component into the interior of the test object;
modifying the noise transmission characteristics of the test component;
measuring new noise levels transmitted to the test object interior through the modified test component;
comparing interior noise level results to determine noise transmitted.
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Accused Products
Abstract
The invention is an apparatus which allows selective testing of aircraft or other vehicular components without requiring disassembly of the vehicle or components. The invention consists of a broad-band noise source 11, a guide 12 to direct the acoustic energy, soft sealing insulation 17 to seal the guide to the noise source and to the vehicle component, and noise measurement microphones 13, 14, both outside the vehicle at the acoustic guide output and inside the vehicle to receive attenuated sound. By directing acoustic energy only to selected components of a vehicle via the acoustic guide, it is possible to test a specific component, such as a door or window, without picking up extraneous noise which may be transmitted to the vehicle interior through other components or structure. This effect is achieved because no acoustic energy strikes the vehicle exterior except at the selected component. Also, since the test component remains attached to the vehicle, component dynamics with vehicle frame are not altered.
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Citations
15 Claims
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1. A method for acoustic testing of interior cabin noise levels in assembled, full-scale vehicles which allows selective testing of installed components and subassemblies comprising the following steps:
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sealing an acoustic guide to a noise source and to a test component such that noise impingement is restricted to the test component only; transmitting noise into the acoustic guide; directing said noise from the acoustic guide on to a component or subassembly of a test object; measuring noise energy delivered to the exterior of the test component; measuring noise energy transmitted through the test component into the interior of the test object; modifying the noise transmission characteristics of the test component; measuring new noise levels transmitted to the test object interior through the modified test component; comparing interior noise level results to determine noise transmitted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for acoustic testing of interior noise levels in a full-scale assembly of a vehicle which allows selective testing of components and subassemblies comprising the following:
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a noise source; an acoustically-insulated guide; acoustic seals between the noise source and the acoustic guide and between the guide and a test component; noise monitors within the guide and within the vehicle assembly interior; means for comparing noise levels within the guide with those within the vehicle assembly; means for adjusting the location of the acoustic testing apparatus with respect to the full-scale assembly. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification